Cardiac Imaging, Nuclear Medicine Department, University Hospital Zurich, Switzerland (A.A.G., R.R.B., P.A.K., O.G.)Applied Imaging Science Laboratory, Radiology Department, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (D.M.)The University of Ottawa Medical School, ON, Canada (D.M.)MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary (A.B., B.M., P.M.-H.)Cardiovascular Biology and Biomechanics Laboratory, Cardiovascular Division, University of Nebraska Medical Center, Omaha (Y.S.C.).